fix(gate-b): fresh-db install path - conditional guards on plugin-table migrations + dual-path convergence migrations

app/plugins/builtins/kommunikation/migrations/0002_system_channel_folders.sql

@@ -0,0 +1,7 @@
+-- Dual-path convergence (Gate B): add columns that Alembic migrations
+-- 0120 (is_system) and 0140 (folder_id) add on the core path. Idempotent
+-- so both install paths converge to the identical schema.
+ALTER TABLE comm_conversations ADD COLUMN IF NOT EXISTS is_system BOOLEAN NOT NULL DEFAULT FALSE;
+CREATE INDEX IF NOT EXISTS ix_comm_conversations_tenant_system ON comm_conversations(tenant_id, is_system);
+ALTER TABLE comm_conversations ADD COLUMN IF NOT EXISTS folder_id UUID;
+CREATE INDEX IF NOT EXISTS ix_comm_conversations_folder ON comm_conversations(folder_id);

app/plugins/builtins/kommunikation/plugin.py

@@ -39,7 +39,7 @@ class KommunikationPlugin(BasePlugin):
             "participant.left",
             "reaction.added",
         ],
-        migrations=["0001_initial.sql"],
+        migrations=["0001_initial.sql", "0002_system_channel_folders.sql"],
         permissions=[
             "comm:read",
             "comm:write",